The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 25, 1997
Filed:
Aug. 16, 1995
Patrick J Curran, Farmington Hills, MI (US);
Juliette J McCoy, South Lyon, MI (US);
Michael A Panganis, Plymouth, MI (US);
David C Waskiewicz, Novi, MI (US);
Bryce A Schwager, Ypsilanti, MI (US);
Edward G Rychlick, Dearborn, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A method and system for monitoring an evaporative purge system for malfunctions and leaks. First, a plurality of predetermined entry conditions are checked for satisfaction. If the plurality of predetermined entry conditions have been met, a flow of vapor in the evaporative purge system is determined. The evaporative purge system is then sealed from atmosphere so as to pull a vacuum on the fuel tank. The vacuum is compared to a predetermined vacuum range. If the vacuum is within the predetermined vacuum range, the vacuum is allowed to stabilize to obtain a stabilized vacuum level. A decrease in the stabilized vacuum level is determined after a predetermined amount of time to obtain a vacuum bleed-up. A vacuum bleed-up acceptance threshold is then determined based on the determined flow of vapor and the vacuum bleed-up is then compared to the vacuum bleed-up acceptance threshold. If the vacuum bleed-up exceeds the vacuum bleed-up acceptance threshold, atmosphere is provided to the evaporative purge system until stabilization. The evaporative purge system is then sealed again to create a pressure build. The pressure build is compared to a pressure threshold. Finally, a malfunction signal is generated if the pressure build is less than the pressure threshold.